Overselling happens when two channels sell the same last unit. The usual cause isn't a bug. It's time: stock is updated in batches, and orders arrive in between.
Why stock drifts
- Inventory is uploaded from a spreadsheet once or twice a day
- Each channel keeps its own count
- Bundles lock up components that other channels think are free
The four rules that fix it
- One source of truth: the warehouse's on-hand stock, not each storefront's.
- Safety buffer: hold back a few units for damages and offline orders.
- Share % and max quantity: decide how much of your stock each channel can see.
- Send zero below a threshold: when stock gets low, show zero everywhere rather than risk a cancellation.
Example
100 units on hand, a 10-unit buffer, an 80% share and a max of 50: each channel sees 50. When stock falls to 14: (14 − 10) × 80% = 3, which is below a threshold of 5, so every channel sees 0.
Make failures visible
Even with good rules, some orders fail (an unmapped SKU, an unserviceable pincode). Park them with a reason and requeue once fixed, instead of losing them. See the sync ledger.
Waretech runs these rules per channel connection for Shopify and Amazon, with Flipkart in early access. Book a demo.